The Oyster Perpetual GMT-Master is the watch for airline pilots, chosen by serious travellers and professionals who fly the world. The Rolex GMT Master is a line of the Rolex Professional Watch Collection designed in collaboration with Pan Am Airways and issued by the airline to their crews on long haul-flights, first launched in 1954. This GMT hand enables crews to set the watch to GMT (Greenwich Mean Time) – or another time zone – using the rotatable 24 hour scale bezel, so that a second time zone could be read.